1. Field of the Invention
The present invention relates to a new and improved process for the preparation of di-polyoxyalkylene hydroxymethylphosphonate.
2. The Prior Art
Di-polyoxyethylene hydroxymethylphosphonate has been prepared by first reacting phosphorus trichloride with formaldehyde. This reaction is followed by hydrolysis to yield hydroxymethyl phosphonic acid and residual chlorine. (See: M. I. Kabachnik and E. S. Shepeleva; Izvest. Akad. Nauk-SSSR, p. 185 (1951). The hydroxymethyl phosphonic acid then is reacted with excess ethylene oxide to produce di-polyoxyethylene hydroxymethylphosphonate.
A side product of the prior art process is bis-chloromethylether, a known carcinogen. (See Federal Register, Volume 39, Number 20, Jan. 29, 1974, page 3757.)